Analogous technical solutions are known from the prior art, see, e.g., the description of USSR patent no. 1229742, which contains the following combination of essential features:                a rectifier (DC voltage source);        a DC-pulse voltage converter, the inputs of which are connected to the outputs of the DC voltage source;        a pulse voltage-DC converter, the inputs of which are connected to the outputs of the DC-pulse voltage converter (DLC filter);        a first resistive voltage divider, the corresponding outputs of which are connected to the outputs of the DLC filter;        a line stabiliser, the inputs of which are connected to the outputs of the pulse voltage-DC converter;        a second resistive voltage divider, one of the outputs of which is connected to the output of the line stabiliser and the other output of which is connected to the negative output of the DC voltage source;        a load, the first output of which is connected to the output of the line stabiliser and the second output of which is connected to the negative output of the DC voltage source;        a control circuit, the first input of which is connected to the output of the DC output voltage selector, the second input of which is connected to the output of the second resistive voltage divider, and the output of which is connected to the control input of the DC-pulse voltage converter.        
The following features are common to the first proposed embodiment of the device for obtaining DC voltage and the above-described analogous technical solution:                a DC voltage source;        a DC-pulse voltage converter, the inputs of which are connected to the outputs of the DC voltage source;        a pulse voltage-DC converter, the corresponding inputs of which are connected to the corresponding outputs of the DC-pulse voltage converter;        a DC output voltage selector (first resistive divider), the corresponding outputs of which are connected to the outputs of the pulse voltage-DC converter;        a control circuit, the first input of which is connected to the output of the DC voltage output selector and the output of which is connected to the control input of the DC-pulse voltage converter.        
The following features are common to the second proposed embodiment of the device for obtaining DC voltage and the above-described analogous technical solution:                a DC voltage source;        a DC-pulse voltage converter, the inputs of which are connected to the outputs of the DC voltage source;        a pulse voltage-DC converter;        a DC output voltage selector, the corresponding outputs of which are connected to the outputs of the DC-pulse voltage converter;        a control circuit, the first input of which is connected to the output of the DC output voltage selector.        
An analogous technical solution is also known, see U.S. Pat. No. 6,747,420B2, selected as the closest prior art, for a prototype comprising the following combination of essential features:                a DC voltage source;        a DC-pulse voltage converter, the inputs of which are connected to the outputs of the DC voltage source;        a pulse voltage-DC converter having a positive output for connection to one of the outputs of the load, and the inputs of which are connected to the outputs of the DC-pulse voltage converter;        a load, one of the outputs of which is connected to the positive output of the pulse voltage-DC converter;        a regulator, one output of which (the first input) is intended for connection to the other output of the load;        a proportional regulator, one output of which is connected to the control (second) input of the regulator;        a DC output voltage selector, the corresponding outputs of which are connected to the outputs of the DLC filter;        a control circuit, the first input of which is connected to the output of the DC output voltage selector, the second input of which is connected to the output of the regulator, and the output of which is connected to the control input of the DC-pulse voltage converter.        
The following features are common to the first proposed embodiment and the prototype:                a DC voltage source;        a DC-pulse voltage converter, the input of which is connected to the outputs of the DC voltage source;        a pulse voltage-DC converter having a positive output for connection to one of the outputs of the load, and the corresponding inputs of which are connected to the corresponding outputs of the pulse voltage-DC converter;        a regulator, one output of which (the first input) is intended for connection to the other output of the load;        a proportional regulator, one output of which is connected to the control (second) input of the regulator;        a DC output voltage selector, the corresponding outputs of which are connected to the outputs of the DLC filter;        a control circuit, the first input of which is connected to the output of the DC voltage output selector and the output of which is connected to the control input of the DC-pulse voltage converter.        
The following features are common to the second proposed embodiment and the prototype:                a DC voltage source;        a DC-pulse voltage converter, the inputs of which are connected to the outputs of the DC voltage source;        a pulse voltage-DC converter having a positive output for connection to one of the outputs of the load;        a regulator, having a first input for connection to the other output of the load;        a proportional regulator, one output of which is connected to the control (second) input of the regulator;        a DC output voltage selector, the corresponding outputs of which are connected to the outputs of the DLC filter;        a control circuit, the first input of which is connected to the output of the DC output voltage selector.        
The technical result that cannot be attained with any of the above analogous technical solutions is ensuring stable DC voltage on the load over a wider range of output voltages with a substantial reduction in the magnitude of the pulsed component in the output voltage and output current.
The aforementioned technical result is unattainable, in the known-art devices for analogous purposes, because the issues of ensuring stable DC voltage on the load over a wider range of output voltages, whilst substantially reducing the magnitude of the pulsed component in output voltage and current, were not given the attention they warranted, because it was believed that the range of stable DC voltage obtained on the load and the magnitude of the pulsed component of the output voltage and current completely satisfied current requirements.
Taking into account the characteristics and an analysis of the analogous prior-art solutions, it can be concluded that the objective of providing devices for obtaining stable DC current on a load over a wider range of output voltages, whilst substantially reducing the magnitude of the pulsed component in the output voltage and current, remains current even today.